Experts maybe freezing bananas if Celsius drops (3,5)

I believe the answer is:
old hands
'experts' is the definition.
(old hand is a kind of expert)
'freezing bananas if celsius drops' is the wordplay.
I cannot quite see how this works, but
'bananas' could be 'hand' (I've seen this before) and 'hand' is found within the answer.
The remaining letters 'olds' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'maybe' is the link.
Can you help me to learn more?
(Other definitions for old hands that I've seen before include "Experienced folk" , "Experienced people who have given long service" , "Experts" , "Experienced persons" , "Veterans" .)
